Alert archive / Massachusetts / Flash Flood Warnings in 2009

Flash Flood Warning 22, NWS Boston/Norton, MA

September 12, 2009Barnstable County, Plymouth County, Massachusetts

NWS Boston/Norton, MA issued this flash flood warning at Sep 12, 2009, 6:55 PM EDT for Barnstable County, Plymouth County, Massachusetts. It was in force for 3 hr. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 12, 2009, 6:55 PM EDT (22:55 UTC)
Expired: Sep 12, 2009, 10:15 PM EDT
In force: 3 hr
Issued by: NWS Boston/Norton, MA
Area: Storm-based polygon
Flood severity: None

Counties Barnstable County, MA, Plymouth County, MA

The radar

The Boston radar (KBOX), 49 km from the middle of the area, began a volume at 22:57 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Sep 12, 7:03 PM EDT	FLOOD	Bourne, MA	ROUTE 130 FLOODED WITH UP TO 8 INCHES OF WATER.
Sep 12, 8:12 PM EDT	FLOOD	Bourne, MA	3 FEET OF WATER ON ST. MARGARETS STREET.
Sep 12, 8:12 PM EDT	HEAVY RAIN 6	Bourne, MA	MEASURED IN BUZZARDS BAY SECTION OF BOURNE...EVENT TOTAL.
Sep 12, 8:29 PM EDT	FLOOD	Bourne, MA	BUZZARDS BAY DRIVE FLOODED...ALONG WITH SEVERAL BASEMENTS AND A FEW BUSINESSES.
Sep 12, 9:00 PM EDT	FLASH FLOOD	Bourne, MA	BOURNEDALE ROAD ON THE BOURNE/PLYMOUTH LINE HAS A SECTION OF PAVEMENT WASHED OUT.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Chatham, MA (KCHH), launched 12:00Z, 10.9 hours before the alert went out and 53 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 150 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 505 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 107 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WGUS51 KBOX 122255
FFWBOX
MAC001-023-130015-
/O.NEW.KBOX.FF.W.0022.090912T2255Z-090913T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
655 PM EDT SAT SEP 12 2009

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL BARNSTABLE COUNTY IN SOUTHEAST MASSACHUSETTS...
  EAST CENTRAL PLYMOUTH COUNTY IN SOUTHEAST MASSACHUSETTS...

* UNTIL 815 PM EDT

* AT 648 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A SLOW MOVING COMPLEX OF THUNDERSTORMS NEAR BOURNEDALE...MOVING SLOWLY
  NORTHWEST AROUND 10 MPH. HOURLY RADAR RAINFALL ESTIMATES HAVE INCREASED
  TO BETWEEN 2 AND 3 INCHES PER HOUR. THIS MAY RESULT IN LOCALIZED 
  FLASH FLOODING OF ROADWAYS AND OTHER LOW LYING AREAS JUST WEST
  OF THE CANAL NEAR BOURNEDALE NORTHWESTWARD TO THE SOUTHERN PORTIONS
  OF PLYMOUTH. 

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY...INCLUDING UNDERPASSES. THE WATER MAY BE TOO DEEP TO ALLOW
VEHICLES TO CROSS SAFELY...OR THE ROADWAY MAY BE UNDERMINED.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.

&&

LAT...LON 4171 7063 4172 7064 4173 7063 4173 7065
      4183 7075 4194 7055 4185 7052 4182 7054
      4178 7050 4177 7050

$$

MLE

3 follow-up statements

000 
WGUS71 KBOX 122349
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
749 PM EDT SAT SEP 12 2009

MAC001-023-130015-
/O.CON.KBOX.FF.W.0022.000000T0000Z-090913T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PLYMOUTH MA-BARNSTABLE MA-
749 PM EDT SAT SEP 12 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM EDT FOR 
WESTERN BARNSTABLE AND SOUTHEAST PLYMOUTH COUNTIES...

AT 742 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A CLUSTER OF SHOWERS AND THUNDERSTORMS PRODUCING FLASH FLOODING 
OVER THE WARNED AREA. THE HEAVIEST RAIN WILL CONTINUE TO FALL NEAR
THE BARNSTABLE...PLYMOUTH COUNTY LINE EXTENDING SLIGHTLY NORTHWEST
OF THERE BY 1 TO 3 MILES. RADAR RAINFALL RATES CONTINUE TO BE 3 TO 4
INCHES PER HOUR IN THIS AREA. DANGEROUS FLASH FLOODING IS LIKELY
OCCURRING OR GETTING READY TO. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS OCCUR
IN AUTOMOBILES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS...OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER
GROUND.

&&

LAT...LON 4171 7063 4172 7064 4173 7063 4173 7065
      4183 7075 4194 7055 4185 7052 4182 7054
      4178 7050 4177 7050

$$
EKSTER

000 
WGUS51 KBOX 130011
FFWBOX
MAC001-023-130215-
/O.EXT.KBOX.FF.W.0022.000000T0000Z-090913T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TAUNTON MA
811 PM EDT SAT SEP 12 2009

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL BARNSTABLE COUNTY IN SOUTHEAST MASSACHUSETTS...
  EAST CENTRAL PLYMOUTH COUNTY IN SOUTHEAST MASSACHUSETTS...

* UNTIL 1015 PM EDT

* AT 807 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM NEAR BOURNE...OR 12 MILES SOUTH
  OF PLYMOUTH...MOVING NORTH AT 5 MPH. RADAR RAINFALL RATES OF
  3 TO 4 INCHES PER HOUR HAVE BEEN INDICATED IN THE WARNED AREA
  AND SERIOUS FLOODING AND FLASH FLOODING IS OCCURRING. THE RAINFALL
  SHOULD BEGIN TO TAPER OFF BY 9 PM...BUT RUNOFF WILL CONTINUE EVEN
  AFTER THE RAIN ENDS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT
TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY...INCLUDING UNDERPASSES. THE WATER MAY BE TOO DEEP TO ALLOW
VEHICLES TO CROSS SAFELY...OR THE ROADWAY MAY BE UNDERMINED.

FLASH FLOODING IS OCCURRING OR IS IMMINENT. MOST FLOOD RELATED DEATHS
OCCUR IN VEHICLES. DO NOT ATTEMPT TO CROSS WATER COVERED BRIDGES...
DIPS OR LOW WATER CROSSINGS. NEVER TRY TO CROSS A FLOWING STREAM...
EVEN A SMALL ONE...ON FOOT. TO ESCAPE RISING WATER MOVE UP TO HIGHER
GROUND.

&&

LAT...LON 4171 7063 4172 7064 4173 7063 4173 7065
      4183 7075 4194 7055 4185 7052 4182 7054
      4178 7050 4177 7050

$$
EKSTER

000 
WGUS71 KBOX 130131
FFSBOX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
931 PM EDT SAT SEP 12 2009

MAC001-023-130215-
/O.CON.KBOX.FF.W.0022.000000T0000Z-090913T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PLYMOUTH MA-BARNSTABLE MA-
931 PM EDT SAT SEP 12 2009

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM EDT FOR WEST
CENTRAL BARNSTABLE AND EAST CENTRAL PLYMOUTH COUNTIES...

RAINFALL HAS DIMINISHED IN INTENSITY HOWEVER SPOTTERS INDICATE 
NUMEROUS ROAD CLOSURES MOSTLY IN THE WAREHAM AND BOURNE VICINITY
IN SOUTHEASTERN PLYMOUTH AND WESTERN BARNSTABLE COUNTIES WITH RUNOFF 
STILL CAUSING FLOODED CONDITIONS. RADAR ESTIMATES INDICATE ALMOST 
SEVEN INCHES OF RAINFALL IN THIS AREA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. MOVE
UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS
SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 4171 7063 4172 7064 4173 7063 4173 7065
      4183 7075 4194 7055 4185 7052 4182 7054
      4178 7050 4177 7050

$$

The office that day

Everything else NWS Boston/Norton, MA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 12, 4:41 AM EDT	Small Craft Advisory for Hazardous Seas	BOX		37 hr
Sep 12, 9:07 AM EDT	Areal Flood Advisory	BOX	Essex, Middlesex, Norfolk, Plymouth, Suffolk	3 hr
Sep 12, 5:45 PM EDT	Areal Flood Advisory	BOX	Barnstable, Plymouth	105 min

Nearby

Flash Flood Warnings in Massachusetts, 2009 Every flash flood warning in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.